Koyuki

Koyuki is one of Mahiru's childhood friends and classmates. He is often seen with Ryusei.

History
When Koyuki was a child, he was friends with Mahiru and Ryusei. When Mahiru's parents died, Koyuki offered to listen if Mahiru ever needed to talk to someone. He is shown to be very worried and looks out for Mahiru, not unlike the way he is currently. When Ryusei suggests that the three of them play soccer to cheer Mahiru up and gets declined, Koyuki declares that Mahiru hates soccer.

Story
Koyuki is first seen in chapter one preparing for the cultural festival with Mahiru, Ryusei, and Sakuya.

When the four of them are stopped on the street by Belkia, who claims to be a magician, Koyuki is interested and thinks he is cool. His opinion of Belkia soon changes once he attacks Ryusei. After Ryusei is injured, Koyuki holds him in his arms and cries out for help. Belkia then sees that he is alive and asks if he wants to "Join his friend". Mahiru then jumps on top of Belkia to stop him.

The next day at school, Mahiru rushes in, concerned for Ryusei. Koyuki tells Mahiru that Ryusei was injured in an accident. Mahiru tries to explain that a vampire magician attacked them the day before, but Koyuki asks if he is telling one of Sakuya's fairytales.

Trivia
Koyuki
 * He seems to be very fond of Kuro in his cat form. He often calls him cute and offers him cookies.
 * He is spooked by Sakuya's vampire stories.
 * He likes karaoke.